The invention relates to a method for reading programs into a device, which processes data by means of a processor according to a program stored in a program memory, and by which program data are supplied as a data stream by a programming device to the program memory of the device to be programmed.
The invention further relates to a device for reading programs into a device, which processes data by means of a processor according to a program stored in a program memory, and in which program data are adapted to be supplied as a data stream by a programming device to the program memory of the device to be programmed.
In the sense of the invention, xe2x80x9cprogramxe2x80x9d can be a sequence of data processing steps for processing data. However, xe2x80x9cprogramxe2x80x9d is also an operating system or the software-determined configuration of hardware components of the device.
It is known to transmit programs in devices controlled by processors by means of data carriers, on which the program is stored and from which the program is read into the data memory of the device by means of a reading unit. Many devices controlled by processors do not allow to provide a drive unit for a data carrier having a reading unit in the device itself. Then the program has to be transmitted through a cable from a programming device, for example a computer.
A further possibility is to exchange program modules or program memories in the device.
All of these cases require mechanical intervention into the device controlled by processors. A plug of a cable has to be inserted or components have to be replaced. This is cumbersome and requires eventually the device to be reconstructed and/or opened. Plug bushings require space which often is not available. As a result of the mechanical intervention, damage can be made by electrostatic discharge (EDS). The transmission of the program data can be disturbed by outer electric or electromagnetic influences. Protection devices, for example against EDS, have to be removed in order to transmit the program data.
It is known to transmit data by wireless transmission between devices, for example between personal computers, by means of a light transmitter and a light receiver. These data are information to be processed or stored, and are not program data, which determine the program for processing such information by means of the processor. These data are written into a working memory, not into the program memory of the device.
According to the prior art, programs of the type defined above are changed through data carriers and/or cables or through exchange of components.
Obviously there has been made a distinction between the xe2x80x9cvolatilexe2x80x9d data to be processed, for example measuring values to be processed, and the xe2x80x9cfixedxe2x80x9d program data, which determine the execution of the data processing. The latter has been input xe2x80x9cconventionallyxe2x80x9d through cables or the like, which obviously has been found to be the safest method.
Through European patent application EP-A-0 457 940 it is known to input updates into an electronic device provided with a processor by means of a programming device to reprogram the device. It is also suggested to effect a wireless transmission of the programs by using infrared light.
Using this type of programming there is a risk of transmission errors and, thus, of programming errors.
It is the object of the invention, with a method and a device for reading program data of the type described above, to avoid errors, which may occur as a result of mechanical connections between the programming device and the device to be programmed, as a result of mechanical intervention into the device to be programmed, or as a result of errors when using wireless data transmission.
According to the invention this object is achieved by a method having the method steps of:
(a) activating a light transmitter in accordance with the program data, such that the light transmitter generates digital light signals in accordance with the program data,
(b) receiving the light signals with a light receiver fixed to the device to be programmed,
(c) applying the signals of the light receiver of the device to be programmed to the program memory of this device, wherein
(d) information is transmitted through light signals in both directions between the programming device and the device to be programmed, and
(e) the transmission of the program data is effected interactively between the programming device and the device to be programmed,
in which, according to the invention,
(f) after transmission of the program data from the programming device to the device to be programmed, the program data thus transmitted and stored in the program memory of the device to be programmed are retransmitted through light signals to the programming device for verification.
A device for carrying out this method comprises
(a) a light transmitter and means for digitally activating the light transmitter with the program data supplied from the programming device and generating corresponding pulsed infrared light signals,
(b) a light receiver fixed to the device to be programmed, to which the light signals are applied and which generates program data from pulsed signals of the light receiver according to a log predetermined for the light transmitter and the light receiver, and
(c) means for reading the program data thus obtained into a program memory of the device to be programmed, wherein
(d) both the programming device and the device to be programmed each have a light transmitter and light receiver unit, such that the data are transmittable interactively,
(e) the device to be programmed comprises means, which, after transmission of the program data from the programming device to the device to be programmed, are adapted to retransmit to the programming device the program data thus transmitted and stored in the program memory of the device to be programmed through the light transmitter unit of the device to be programmed and the light receiver unit of the programming device, and
(f) the programming device comprises verification means for verification of the program thus transmitted to the device to be programmed and retransmitted from it.
Thus, according to the invention, the loading of the program, that means the input of the program data in to the program memory, is effected through wireless transmission and light between the light transmitter and light receiver, the light receiver being fixed to the device. In this manner, no mechanical interventions into the device are required. Damage due to electrostatic discharge cannot occur. The light receiver only requires small space. Disturbances due to electromagnetic influences do not occur. Due to retransmission of the program data and verification of the same, it is ensured, when using the wireless transmission, that no program errors can occur or that such program errors are detected.
It has also been found that in this manner programs can be read through wireless transmission into the program memory with sufficient security. Unintentional changes of the program, for example when data to be processed are input through light transmitter and light receiver, are avoided by the mode of transmission.
Modifications of the invention are subject matter of the sub-claims.
An embodiment of the invention will now be described in greater detail with reference to the accompanying drawings.